Any
engineered product
can be listed is one of two ways.
1) Knowing the specified in that a product has
been designed to perform, tests can be conducted
that demonstrate each for fully operational
while at the same time searching for errors
in each tn, called BLACK
BOX TESTING. It alludes to test that
are conducted at the S/W interface.

Although they are designed to uncover errors,
black-box tests are and to demonstrate that
S/W fn’s are designed to uncover errors
black box tests are and to demonstrate that
s/w fn’s are operational, that ip is properly
accepted and op is correctly of external info.
(eg. Data) is maintained. A black – box
test examines little regard for the internal
logical structure of the software testing.

2)
Knowing the internal working of a product, tests
can be conducted to ensure that all internal operations
are performed according to spec and all internal
components have been adequately exercised. This
is called WHITE BOX TESTING
or GLASS BOX TESTING.
Which box testing assert an close examination
of procedural detail. Logical paths through the
s/w are listed by providing test cases that exercise
specific sets of and/ or loops. The status of
the program can be examined at various pts to
det of the expected or asserted status corresponds
to the actual status. Here the test case design
is using structure of the procedural design.